Because of some changes made in the 2024 editions of the I-Codes, I have updated this Decoded article addressing when to use fail secure vs. fail safe electrified hardware.
This post was published in Doors & Hardware
.This question comes up a lot…
“When do I need to specify/supply/install fail safe electrified hardware and when should I choose fail secure electrified hardware?”
First, some basic definitions:
- Fail safe products are unlocked on the access side when power is removed. Power is applied to lock the door.
- Fail secure products are locked on the access side when power is removed. Power is applied to unlock the door.
- Fail safe / fail secure typically refers to the status of the secure side (key side, outside, access side) of the door.
- Most products that are not special locking arrangements provide free egress whether they are fail safe or fail secure (see below).
An electric strike replaces the regular strike for a lockset or panic hardware. For a single door it mounts in the frame, for a pair of doors it mounts in the inactive leaf or on a mullion. The lockset or panic hardware still functions as it normally would…free egress is available at all times, except in the case of double-cylinder institutional function locks, which are not common.
The spring-loaded keeper on the electric strike controls the latchbolt of the lockset or panic hardware. When access is allowed, the keeper is free and the latchbolt can be pulled through the keeper so the door can be opened. When the strike is secure, the keeper secures the latchbolt and prevents the door from being opened from the access side. In most cases, a key can be used to retract the latchbolt from the secure side of the door to allow access if a manual override is needed. And because the lock or panic hardware functions independently of the electric strike, a building occupant can exit by turning the lever or pushing the touchpad of the panic hardware, regardless of whether the electric strike is fail safe or fail secure.
When electric strikes are installed on fire door assemblies, fail secure strikes MUST be used per NFPA 80 – Standard for Fire Doors and Other Opening Protectives, which requires the strikes to be listed for use on a fire door assembly. I specify fail secure strikes in almost all applications, except when access is required upon fire alarm activation. There are very limited situations where access upon fire alarm is required (see below regarding stairwell re-entry and elevator lobby exit access doors). I have been asked, “What about firefighter access?” The use of an electric strike really doesn’t change anything with regard to firefighter access. Their method for access on a door with a mechanical lockset can still be used. That might be a key or access-control credential in the key box, or a tool, depending on what type of hardware is on the door.
You might think, “Let’s just make all electrified products fail safe…then I know there won’t be a problem.” Well, don’t forget that electric strikes on fire doors MUST be fail secure so the door is positively latched if there is a fire. But in addition, there are security concerns. Should the building or area be unlocked and allow free access every time there is a power failure? A breach of security can be extremely dangerous for building occupants, along with the potential for loss or damage. That’s not a liability I’m willing to take on.
An electromechanical lock is a lockset that has been electrified, so it can be controlled by a credential reader, remote release, or other access control device. Most electromechanical locksets allow free egress at all times. There are double-cylinder electromechanical locksets that do not allow free egress, just like double-cylinder mechanical locksets, but neither of those should be used on any door that is required for egress unless prescriptively allowed by the adopted code. Note that when you see a lock with two key cylinders, it may be a classroom security lock (which allows free egress), not an institutional function lock (which does not allow free egress).
A fail secure electromechanical lockset is locked on the secure side when there is no power to the lock. To unlock it, power is applied and the lever can then be turned to retract the latch. The latch remains projected until the lever is turned.
A fail safe electromechanical lockset is locked when power is applied, and unlocked when power is removed. When power is removed, the lever can be turned to retract the latch. Fail safe electromechanical locks are typically used for stairwell doors providing re-entry. The lock is constantly powered so that the lever on the stair side is locked. During a fire alarm, the lever on the stair side is unlocked (power removed) either by the fire alarm or a signal from the fire command center (or both), depending on which code has been adopted.
Beginning with the 2024 edition of the International Building Code (IBC), the code will prescriptively require fail safe electrified locks on stairwell doors to unlock upon any of the following conditions:
- A signal from the fire command center, if present, or a signal by emergency personnel from a single location inside the building’s main entrance
- Activation of a fire alarm signal (where present) in an area served by the stairwell
- Power failure to the electric lock or locking system
Building occupants may then leave the stairwell to find another exit if necessary. The locks always allow free egress into the stair, with the exception of the stair discharge door, which can be mechanically or electrically locked on the outside but allows egress out of the stairwell.
There are two other locations where fail safe locks are common. One is in health care facilities, on doors serving areas where patients require containment for their safety or security. Doors with controlled egress locks may be locked indefinitely, but must be able to be unlocked by clinical staff if emergency evacuation is needed. In addition, the model codes mandate certain emergency release measures to automatically allow egress. Note that there are exceptions related to behavioral health facilities and areas where infant abduction systems are in use.
The other common location for fail safe locks is on an exit access door serving an elevator lobby. NFPA 101 – Life Safety Code has included a section for many years that allows doors between an elevator lobby and a tenant space to be electrically locked. The 2024 edition of the IBC will address this application in a new section that requires a fail safe lock, a telephone or other two-way communication device in the elevator lobby, as well as listing other safety criteria that must be met.
Note that in these applications – stairwell reentry, controlled egress in health care, and elevator lobby exit access doors – various types of fail safe locks may be used. This includes fail safe electromechanical locks, fail safe trim for panic hardware or fire exit hardware, or electromagnetic locks. If the door is not fire rated, it’s possible for a fail safe electric strike to be used in these applications, but it is not common.
Electrified panic hardware trim refers to the outside lever on panic hardware or fire exit hardware. It operates the same way that an electromechanical lock does – the power controls whether the outside lever can be turned or not. The latch remains projected until the lever is turned, and free egress is always available by pushing the touchpad or crossbar of the panic hardware.
Fail safe electrified trim for fire exit hardware is used for stairwell doors providing re-entry. Fail safe trim is less commonly used for controlled egress in health care because the doors would typically swing out of the unit, but it’s possible that fail safe trim could be used on elevator lobby doors (see above for more info). Most other doors are not required to allow access upon fire alarm, so I typically use fail secure electrified panic hardware trim in other locations. Keep in mind that the stair discharge door is not required by code to unlock upon fire alarm. The door between the stairwell and the roof MAY be required/desired to be fail safe, but this is not typical and is not a requirement of the I-Codes or NFPA 101. I have only worked on a few projects during my career where the path of egress led onto the roof.
Electric latch retraction (EL/QEL) is a function that is most commonly used on panic hardware or fire exit hardware but is also available on locksets. EL devices (or QEL for the Von Duprin “Quiet” EL) are only available fail secure. When power is applied, the latch retracts automatically, and stays retracted as long as power is present. When power is removed, the latch is projected, securing the door. Again, free egress is provided via the touchpad of the panic hardware. EL/QEL devices are sometimes used on fire doors, to allow push/pull function during normal use, and provide positive latching during a fire alarm (a signal from the fire alarm system to the power supply is needed). Electric latch retraction devices are often used with automatic operators, so the latch is retracted before the door begins to open. Electric strikes can perform this function as well. Fail safe or fail secure products can be used in this application, but I typically use fail secure except in the very rare case where access is required upon fire alarm. Electromechanical locks and electrified panic hardware trim are not used with automatic operators because the latch is not retracted until someone turns the lever; this would prevent the auto operator from opening the door.
An electromagnetic lock is an electromagnet that mounts on the frame, with a steel armature mounted on the door. When power is applied to the magnet, it bonds to the armature, securing the door. Electromagnetic locks are only available fail safe. When power is removed, the electromagnetic lock unlocks.
Because a mag-lock does not provide free egress like other electrified hardware, release devices are required by code in order to allow egress. An electromagnetic lock that is released by door-mounted hardware (like a request-to-exit switch in panic hardware), is required to unlock upon loss of power. If the electromagnetic lock is released by a sensor detecting a building occupant approaching the door on the egress side, the lock must also unlock upon actuation of a push button located beside the door, upon actuation of the fire alarm / sprinkler system, and upon loss of power.
So, to recap:
- Fail safe locks should be used on stairwell doors requiring re-entry, doors in health care facilities that are equipped with controlled egress locks, exit access doors serving elevator lobbies, and any other doors that must allow free access upon fire alarm or power failure.
- Fail safe electric strikes can’t be used for stairwell re-entry, because fire doors require fail secure electric strikes for positive latching (electric locks on fire doors are not required to be fail secure – only electric strikes).
- Be aware that when a fail safe product is used, the door will be unlocked whenever there is a fire alarm or power failure, which is an obvious security risk.
- Electric latch retraction panic hardware and locksets are only available fail secure – the latch projects when power is removed.
- Electromagnetic locks are only available fail safe – there is no magnetic bond when power is removed.
- Fail secure products are more common than fail safe, due to security concerns. Power consumption may also be an issue. Fail secure products provide security when there is no power applied.
- Most electromechanical locks allow free egress at all times, regardless of whether they are fail safe or fail secure.